A method of performing a remote lesson using player pianos has been proposed. In this type of method, a controller that is connected to a player piano on the transmission side and a controller that is connected to a player piano on the reception side are connected via a network. When a model musical performance is performed by an instructor on the player piano on the transmission side, that model musical performance is reproduced on the player piano on the reception side. Specifically, when musical-performance data in the MIDI (Musical Instrument Digital Interface) format, which represents played sounds, is generated in accordance with the playing of the instructor, the generated musical-performance data is transmitted from the controller on the transmission side to the controller on the reception side. The reception-side controller outputs that musical-performance data to the player piano. The player piano, based on that musical-performance data, generates sounds by the string-striking of hammers and performs automatic playing. Also, the instructor, while performing the model musical performance with the player piano, provides guidance by voice as necessary. The voice of the instructor is picked up by a microphone connected to the transmission-side controller, transmitted to the reception-side controller via the aforementioned network, and emitted from a speaker that is connected to the controller. Thereby, the practicing person, while hearing the model musical performance, can receive instruction by the voice of the instructor.
Adjustments are made to the orientation, frequency characteristics, and sensitivity of the microphone on the transmission side so as to be suited to picking up the instructor's voice. However, despite that the played sounds being emitted from the player piano can end up being picked up during the model musical performance of the instructor. For that reason, on the reception side, the played sounds based on the musical-performance data that has been transmitted and the played sounds that have been picked up by the microphone on the transmission side and transmitted to the reception side are both played back. When there is a shift in the playback timing of the played sounds based on the musical-performance data output from the player piano and the played sounds picked up by the microphone, a problem occurs of it being extremely hard to hear for the practicing person on the reception side. To solve this problem, a method has been proposed in Patent Document 1 of shutting off the communication path of sounds picked up by the transmission-side microphone when the instructor is playing the piano.